Protein consumption and determinants in community dwelling older adults using the National Diet and Nutrition Survey (NDNS) years 9-11: A cross-sectional study.

Introduction

Reference nutrient intake for protein amongst the general population is 0.75 grammes of protein per kilogram of body weight per day (g/kg BW/d). Expert groups recommend healthy adults over 65years have 1.0-1.2g/kg BW/d to support good health and maintain functionality (Deutz, Bauer and Barrazoni, Clinical Nutrition, 33(6):929-36). A recent paper suggested age specific recommendations of 1.2g/kg BW/d (Dorrington, Fallaize and Hobbs, Journal of Nutrition, 150(9):2245-2256).

This study aimed to quantify percentage of community dwelling older adults meeting recommendations for protein intake and explore factors associated with low consumption.

Methods

The study population comprised >65s completing the NDNS survey years 9-11 (2016-2019)*. Dietary intake was recorded in food diaries. Protein consumption was calculated as grammes per kilogram adjusted body weight per day (g/kg aBW/d). Adjustment made for body mass index (BMI) below 22kg/m² and above 27kg/m². Percentage of participants meeting protein recommendations for 0.75, 1.0 and 1.2g/kg BW/d was calculated. Chi-squared test for independence was utilised to determine association between social, health and lifestyle factors and low protein intake.

Results

Data from 385 participants were included; 43% male, 98% white. Mean protein intake was 0.98g/kg aBW/d (SD ±0.25). Prevalence of protein intake below 0.75g/kg aBW/d was 16.4% (n=63), below 1.0g/kg aBW/d was 52.2% (n=201) and below 1.2g/kg aBW/d 82.1% (n=316).

Current and ex-regular smoking was associated with protein intake <1g/kg aBW/d (p=0.01). No other analysis reached statistical significance although prevalence of low protein intake was higher in those without their own teeth (p=0.08), use of dentures (p=0.14) and BMI of 27-30kg/m² (p=0.09).

Conclusion

A large percentage of older adults are below expert recommendations for protein intake. There is a need for clarity over recommendations so that a clear public message can be given to optimise health and function in ageing. Factors influencing poor protein intake require further examination.

*University of Cambridge, MRC Epidemiology Unit, NatCen Social Research. (2023). National Diet and Nutrition Survey Years 1-11, 2008-2019. [data collection]. 19th Edition. UK Data Service. SN: 6533, DOI: http://doi.org/10.5255/UKDA-SN-6533-19